EP 0239181 A2 19870930 - Interrupt requests serializing in a virtual memory data processing system.
Title (en)
Interrupt requests serializing in a virtual memory data processing system.
Title (de)
Serialisierung von Unterbrechungsanforderungen in einer Datenverarbeitungsanlage mit virtuellem Speicher.
Title (fr)
Sérialisation de demandes d'interruption dans un système de traitement de données à mémoire virtuelle.
Publication
Application
Priority
US 81945986 A 19860116
Abstract (en)
In a virtual memory priority interrupt data processing system, system events are logically serialised, because each event causes a different predetermined interrupt servicing routine to be executed, which processes virtual pages in a manner that requires data structures that record the current status of virtual pages to be updated to reflect the change of state resulting from processing. The system events to be serialised include the interrupt that is generated as a result of a page fault, the interrupt that is generated as a result of a paging I/O completion operation that resolves a page fault by paging in a virtual page from the secondary storage device, and lastly, interrupts that are generated in response to a supervisory call to a paging service, such as create or destroy segment. These latter supervisory calls cause the status of one or more pages to be changed and, therefore, the data structure which records such changes must also be updated. The page fault interrupt handling process is only interruptable by another page fault interrupt, or an I/O. An I/O interrupt merely suspends the page fault handler. At the completion of the routine that services the I/O device interrupt, the page fault handler continues from the point of interruption. A second page fault interrupt, however, is serviced and the first page fault is restarted at the beginning of its critical section after the second page fault has been serviced. I/O page fault completion interrupts are placed in a queue. The page faulting process is executed in a mode which delays processing this queue, so these interrupts are serialised after the page fault handling interrupts. The supervisory calls to paging services routines also are executed in a mode that delays processing of enqueued I/O page fault completion interrupts. These interrupts are, therefore serialised last, relative to the other system events. The paging service routines do, however, honour page fault interrupts which are, therefore, serialised ahead of the supervisory calls to paging services. When the page fault handler completes, the interrupted paging service will be re-started at the beginning of its critical section. All three system events are, therefore, logically serialised to preserve the integrity of all data structures that record current status of virtual pages and page frames in the system.
IPC 1-7
IPC 8 full level
G06F 9/48 (2006.01); G06F 12/10 (2006.01)
CPC (source: EP US)
G06F 9/4812 (2013.01 - EP US); G06F 12/10 (2013.01 - EP US)
Designated contracting state (EPC)
DE FR GB IT
DOCDB simple family (publication)
EP 0239181 A2 19870930; EP 0239181 A3 19900627; EP 0239181 B1 19941207; BR 8700175 A 19871201; DE 3750824 D1 19950119; DE 3750824 T2 19950524; JP H0658648 B2 19940803; JP S62165252 A 19870721; US 4718008 A 19880105
DOCDB simple family (application)
EP 87300111 A 19870108; BR 8700175 A 19870116; DE 3750824 T 19870108; JP 424087 A 19870113; US 81945986 A 19860116